This invention relates to lters and more especially to filters for use in connection with the lubrication system of an internal combustion engmTel-1ere are two different classifications of impurities usually present in the lubricant of an internal combustion engine. One of these impurities may be defined as abrasive particles of such size as to be injurious to the working parts of the engine and the other impurities may be defined as solid particles of suchmnute size as not to be injurious to the working parts of the engine, but give the oil an undesirable color. It is important that all impurities of the first classification be removed from lubricant supplied to the working parts of the engine for protection thereof and it is desirable that impurities of the second classication be removed to improve the general character and appearance of the lubncant.

An objecty of this invention is a lter embracing within a single housing a pair of different type filtering units having a. common dirty oil inlet and individual filtered oil outlets.

In one embodiment of this invention, one filtering 'unit preferably is of the type fully illustrated in the patent to R. P. F. Liddell, No. 2 042,537, and is capable of removing the impurities of the first class while the second filtering unit preferably consists essentially of a thick body of filtering material which is capable of removing the impurities of the second class. The second filtering unit is contained within the iirst filtering unit, thereby providing a compact assembly which is enclosed within a single housing. Means are provided Within the casing for dividing the ol to be ltered into two streams, one of which flows only through .the first ltering unit and the other ofv which ows only through the second filtering unit and each stream is discharged from the filter through a separate outlet.

Other objects, novel features and advantages of this invention will become apparent from the following specification and accompanying drawherein:

1 is a vertical section through one embodiment ofthe invention; l

Fig. 2 is a section on the hne 2--2 of Fig. l,

rtiall broken away; lmFig. 3Y is a section on the line 3-3 of Fig. l, anliig. 4 is a section on the line 4*-4of Fig. 1.

In the embodiment of the invention illustrated in the drawing, the filter housing comprisesa in place by the head of a hollow bolt I6 threaded into the boss. The outer edge of the spider engages a shoulder I1 formed in the shell I I, thereby holding the shell in assembled relation to the base. A post I8 coaxial of the boss I4 has its lower end threaded into a tapped recess I9 in the base. The post I8 terminates below the upper end of the shell II and is provided at its upper end with a tapped recess 20. A rod 2| extends through an aperture in the cap I2 `and is threaded at its inner end for co-operation with the threads of the tapped recess 20. A head 22 on the rod 2I engages the outer surface of the cap and co-operates therewith to hold the same in assembled relation to the shell I I.

A lter unit assembly 23 has a bushing 24 snugly but removably fitting the interior of the hollow nut I6. 'This assembly comprises a fluted drum or cylinder 25 which supports a, cylindrical filtering element 26 composed of 'a helix of metal ribbon provided on one face with spacing ribs to provide filtering interstices, such a filter being fully illustrated in U. S. Patent No. 2,042,537 of R. P. F. Liddell. The flutes are so formed as to provide longitudinal channels 25a closed at the upper end of the cylinder and open at the lower end. A cap 2Ivsecured to the bushing 24 fits over th'e lower end of the cylinder 25 with its rim contacting the lower end of the helix 26. An annular plug 28 is fitted into the lower end of the cylinder 25 and receives the post I8 in its central aperture. The plug 28 co-operates with the cap 21 to form a header or chamber 21a into which said longitudinal channels 25a discharge. A perforated spacer 28 serves to maintain the cap 2l and plug 28 in predetermined relationship and a tube 30 extends through both the cap 2'I and plug 28.

A second filtering unit assembly 3Iis arranged within the cylinder 25. 'Ihis assembly consists of two imperforate annular end members 32 and two perforate cylindrical members 33 and 34 of which the edges of the member 33'are connected to the outer rims of the end members 32 and the edges of the member 34 areconnected to the surrounds the post I8 and rod 2I^and isfsur- ',1 rounded by a wire mesh tube 35 over which is' arranged 'a layer of fabric 8B, the latter being held in place by a tie member 31 at each end of the tube. The interiorof the container 3| is filled with a body of suitable absorbent filtering material 38. preferably in the form of a spirally wound ribbon of cotton waste. In each end member 32 is provided a recess in which is arranged a gasket 39. The lower gasket 39 rests on an annular platform 4II supported from the plug 28 by a bracket 4I. On the uppergasket 39 rests a `platform 42 having a downturned flange, the outer surface of which engages inwardly projecting oisets 43 formed in a collar 44 extending from the upper end of the cylinder 25. A sleeve 45 is slidably mounted on the rod 2| and has a flange engaging the top surface of the platform 42. A spring 46 tends to force the platform 42 against the top gasket 39, thereby producing a fluid-tight seal therebetween as well as between the bottom gasket 39 and the platform 40. A collar 22a on the rod 2l limits movement of the sleeve 45 on said rod. Aresilient spider 46a carried by the cap I2 engages the upper edge of the collar 44 to hold the assembly 23 in proper position.

In the lower end of the post I8 is provided a central passageway 4'I communicating with the recess I9 and a restricted orifice 48 providing communication into the passageway 41 from the vexterior of the post. The post is fitted snugly by the inner rim of the plug 28 but there is substantial clearance between the post and the inner wall of the bushing 24. The space thus provided communicates with a passageway B in the base leading to one face thereof. A passageway 49 leads from the recess I9 to said face of the base and a passageway 59 leads from such face to the sump.

In the operation of the above-described filter, dirty oil is supplied to the housing through the passageway 50. Some of such oil passes through the interstices in the ltering unit 26 into the channels 25a from which it is discharged into the header 21a formed by the cap 23. From the header, the filtered oil passes through the bushing 24 to the passageway 58 which is suitably connected to the working parts of the engine. The remainder of the oil passes into the interior of the cylinder 25 either through the tube 30 or through the spaces provided by the offsets 43 of the collar 44. Such oil passes through the perforations in the cylindrical member 33 into the body of the filtering material and out of such body through the perforations in the wall 34 into the space between such wall and the post I8 and rod 2|. From this space, the filtered oil passes through the orifice 48 into the passageway 41 and thence through the passageway 49 to the crankcase or other reservoir. A portion of the oil is thus subjected to the action of one type of filtering unit while the remainder of the oil is subjected to the action of another type of filtering unit. The proportion of oil passing through each filtering unit is determined by the size of the orifice 48. Both filtering units are mounted within a single casing, thus avoiding the necessity of duplicate housings and providing a compact arrangement.

The filtering units may be renewed or reconditioned by removal of the cap I2, thereby releasing the platform 42 which can be removed to free the assembly 3l for removal and replacement by a new unit. Also, with the cover removed. the assembly 23 may be lifted out and cleaned in any well-known manner and then replaced.

I claim: v

l. An oil lter comprising a casing. a cylindrical filtering element in said casing, a supporting said cylinder from the interior of said casing, a

body of absorbent filtering material within 'said cylinder, an outlet from the interior of said cylinder, and means requiring all oil flowing from said inlet passageway to said outlet to pass through said body of filtering material.

2. An oil filter comprising a casing, a pair of filtering elements supported within said casing with one ltering element enclosing the other filtering element, an inlet and two outlets for said casing, and means for continuously directing part of the oil in the casing solely through one filtering element to one outlet and the remainder of the oil solely through the other filtering element to the remaining outlet.

3. An oil filter according to claim 2 in which the enclosed filtering element comprises a body of absorbent filtering material and the enclosing filtering element comprises a foraminous metal cylinder. A

4. An oil filter comprising a casing, a cylindrical filtering element in said casing, a closed end supporting cylinder surrounded by said filtering element and formed to provide longitudinal channels open at one end, a cap on said cylinder co-operating with its closed end to form a chamber with which the open ends of said channels communicate, an outlet for said chamber, a tube traversing said chamber and communicating with both the interior and exterior of said cylinder, a body of absorbent filtering material within said cylinder, an outlet from the interior of said cylinder, and means requiring all oil flowing from said tube to said outlet to pass through said body of filtering material.

5. An oil filter comprising a casing, a cylindrical filtering element in said casing, a closed end supporting cylinder surrounded by said filtering element and formed to provide longitudinal channels open at one end, a cap on said cylinder co-operating with its closed end to form a chamber with which the open ends of said channels communicate, an outlet for said chamber, a tube traversing said chamber and communicating with both the interior and exterior of said cylinder, a container within said cylinder, said container comprising a pair of imperforate annular end members and a pair of perforate different diameter cylindrical members connected thereto, a body of absorbent filtering material within said container, means'sealing the inner cylindrical member of said container at the ends thereof, and an outlet leading from said inner cylindrical member.

6. An oil filter comprising a casing, a cylindrical filtering element in said casing, a supporting cylinder surrounded by said filtering element and formed to provide longitudinal channels open at one end, a chamber communicating with the open ends of said channels, an outlet for said chamber, an inlet passageway t0 the interior of said cylinder from the interior of said casing, a container within said cylinder, said container comprising a pair of imperforate annular end members and a pair of periorate diierent diameter cylindrical members connected thereto, a body of absorbent filtering material within said container, means sealing the inner cylindrical member of said container at the ends thereof. and an outlet leading from said inner cylindrical member.

7. A lter comprising a base having a hollow boss, a casing co-operating with said boss to form a housing, a cylindrical ltering element in said housing, a closed end supporting cylinder surrounded by said ltering element and formed to provide longitudinal channels open at one end, a cap on said cylinder co-operating with its closed end to form a chamber with which the open ends of said channels communicate, a sleeve on said cap snugly tting the interior of said boss, a tube traversing said chamber and communicating with both the interior and exterior of said cylinder, a container within said cylinder comprising a pair of spaced imperforate annular end members and a pair of perforate diierent diameter cylindrical members connected thereto, a body boss, a post threaded to said base in spaced relac tion to the inner wall of said boss, a shell cooperating with said base to form a casing, means co-operating with said post for attaching said shell to said base, a cylinder in said casing surrounding said post and formed to provide longitudinal channels open at one end, a cylindrical ltering element surrounding and supported by said cylinder, said cylinder having an end wall adjacent the open end of said channels snugly fitting said post, a cap on said cylinder forming a chamber with said end wall communicating with the open ends of said channels, a sleeve carried by said cap and snugly tting the interior surface of said hollow boss, a. container within said cylinder, said container comprising a pair of spacedimperforate annular end members coaxial with said post and a pair of perforate different diameter cylindrical members connected thereto, means sealing the ends of the inner cylindrical member of said container, a body of absorbent iiltering material in said container, and a passageway in said post communicating with the inner cylindrical member of said container.

9. A lter comprising a base having a hollow boss, a post threaded to said base in spaced relation to the inner wall of said boss, a shell cooperating with said base to form a casing, means co-operating with said post for attaching said shell to said base, a cylinder in said casing surrounding said post and formed to provide longitudinal channels open at one end, a cylindrical filtering element surrounding and supported by said cylinder, said cylinder having an end wall adjacent the open end of said channels snugly iitting said post, a cap on said cylinder forming a chamber with said end walls communicating with the open ends of said channels, a sleeve carried by said cap and snugly fitting the interior Asurface of said hollow boss, a container within said cylinder, said container comprising a pair of spaced imperforate annular end members coaxial with said post and a pair of perforate different diameter cylindrical members connected thereto, a sealing member carried by said post engaging one end of said container, a second sealing member slidably supported by said shell and engaging the other end of said container, resilient means urging vsaid second sealing member toward said rst sealing member, a body of absorbent material in said container, [and a passageway in said post communicating with the inner cylindrical member of said container.